This invention is related to a signal detector for use in digital communication, and more particularly it concerns the signal detector which is used at a signal receiver side in the digital communication by using cables or electric waves.
It is known that the quality of such digital communication become worse when an intersymbol interference occures. In order to prevent such quality degeneration in the digital communication, a lot of trials have been made to obviate such distortion as generated in signals during transmission thereof. In almost all the trials, the impulse response of the transmission system is estimated first, and then receiving signals are equalized based on such estimation, thereby obviating the distortion involved therein. Such technology will be seen in the article, for instance, which is reported by Peter Mousen and entitled "Feedback Equalization for Fading Dispersive Channels" (IEEE Transaction on Information Theory, January 1971, p 56-64).
According to the technology as mentioned above, the linear distortion is removed out satisfactorily. The non-linear distortion, however, which is generated by a non-linear amplifier adopted in the transmission system is hardly removed out by such a prior art having been developed so far.